Motor driven centrifugal blowers for air handling equipment, such as heating, ventilating and air conditioning (HVAC) systems are well known. A typical air handling blower includes a scroll-like housing within which is mounted a centrifugal blower wheel or impeller of a selected diameter and axial length and wherein the housing is adapted or “sized” to operate efficiently with a particular blower wheel or impeller.
However, there are many applications of air handling equipment wherein it is desirable to select the impeller size to accommodate a particular airflow requirement, impeller rotational speed and static or blower discharge pressure requirement, or a change in such requirements. Such performance requirements or desiderata in the equipment market may dictate that many different size blower wheels and associated blower housings be designed and fabricated to meet particular performance requirements of the blower application. Of course, such a situation increases the costs associated with providing products to suit each blower application.
Accordingly, there has been a continuing need and desire to reduce the costs and product complexity associated with providing various blower wheel sizes and associated blower housings which will accommodate the various specific wheel or impeller sizes while meeting the performance requirements of a blower, without adverse effects of increased noise produced by the blower, as well as other parameters of blower performance and operation known to those skilled in the art. In accordance with the present invention, it has been discovered that a particular configuration of blower housing in combination with a particular range of centrifugal impeller sizes provides for operation without sacrificing blower performance and while maintaining reduced noise levels.